It was a Thursday afternoon, and the Form 4 Science lab smelled of antiseptic and old wood. Maya, Lin, and Ravi huddled over their workstation, a neat row of four test tubes clamped to a metal stand. Their teacher, Puan Aishah, had given them a puzzle.
“No reaction,” Maya noted, scribbling in her book. “Copper + copper sulphate → no change. That means copper is low in the reactivity series. It can’t kick itself out of its own salt.”
Only the blue solution. Nothing happened. It remained still, a calm witness. chemistry form 4 experiment 5.1
Ravi carefully dropped a few granules of zinc into the next tube. For a moment, nothing. Then, a miracle. The deep blue colour began to bleed away from the zinc, as if an invisible eraser was moving upwards. Simultaneously, a reddish-brown dust started to bloom on the surface of the zinc granules, like rust forming in fast-forward.
The reaction was instant and violent. The magnesium hissed like an angry cat. The blue solution boiled around the metal, turning pale within seconds. But unlike the zinc, the magnesium didn’t just produce a dusting of copper. It became coated in a hot, fizzing blanket of reddish-brown powder. The test tube grew warm to the touch. It was a Thursday afternoon, and the Form
Lin dropped a small piece of copper wire into the blue liquid. They waited. One minute. Two. The copper sat at the bottom like a sleeping snake. The blue remained blue.
“Look!” Lin gasped. “The blue is disappearing! And… is that copper metal?” “No reaction,” Maya noted, scribbling in her book
“Magnesium!” the class shouted.
Lin nodded, swirling the last of the pale, colourless solution down the sink. “That’s not war,” she smiled. “That’s displacement. And now we know how to prove who belongs where.”
He dropped the ribbon into the final bath of blue.